yading@10: function y=stptpeaks(x, w, N, H, t)
yading@10: % Analysis/synthesis of a sound using the peaks
yading@10: % of the short-time fourier transform
yading@10: % x: input sound, 
yading@10: % w: analysis window (odd size), 
yading@10: % N: FFT size, 
yading@10: % H: hop size,
yading@10: % t: threshold in negative dB, 
yading@10: % y: output sound
yading@10: 
yading@10: M = length(w); % analysis window size
yading@10: N2 = N/2+1; % size of positive spectrum
yading@10: soundlength = length(x); % length of input sound array
yading@10: hM = (M-1)/2; % half analysis window size
yading@10: 
yading@10: pin = 1+hM; % initialize sound pointer at the middle of analysis window
yading@10: pend = soundlength-hM; % last sample to start a frame
yading@10: 
yading@10: fftbuffer = zeros(N,1); % initialize buffer for FFT
yading@10: yw = zeros(M,1); % initialize output sound frame
yading@10: y = zeros(soundlength,1); % initialize output array
yading@10: 
yading@10: w = w/sum(w); % normalize analysis window
yading@10: sw = hanning(M); % synthesis window
yading@10: sw = sw./sum(sw);
yading@10: 
yading@10: while pin<pend
yading@10: xw = x(pin-hM:pin+hM).*w(1:M); % window the input sound
yading@10: fftbuffer(:) = 0; % reset buffer
yading@10: fftbuffer(1:(M+1)/2) = xw((M+1)/2:M); % zero-phase fftbuffer
yading@10: fftbuffer(N-(M-1)/2+1:N) = xw(1:(M-1)/2);
yading@10: 
yading@10: X = fft(fftbuffer); % compute the FFT
yading@10: mX = 20*log10(abs(X(1:N2))); % magnitude spectrum of positive frequencies
yading@10: pX = unwrap(angle(X(1:N2))); % unwrapped phase spectrum
yading@10: 
yading@10: ploc = 1 + find((mX(2:N2-1)>t) .* (mX(2:N2-1)>mX(3:N2)) .* (mX(2:N2-1)>mX(1:N2-2))); % peakss
yading@10: pmag = mX(ploc); % magnitude of peaks
yading@10: pphase = pX(ploc); % phase of peaks
yading@10: num_peak=length(ploc)/2; %Just positive peaks
yading@10: 
yading@10: axis=linspace(0,pi,N2); %Axis for the whole frequency plot
yading@10: axis_peak=axis(ploc(1:num_peak));%Axis for just the peaks plot
yading@10: 
yading@10: subplot(2,1,1); plot(axis,mX); hold on; %Magnitude plot
yading@10: plot(axis_peak,pmag(1:num_peak),'rx');%Magnitude peaks
yading@10: subplot(2,1,2); plot(axis,pX); hold on; %Phase plot
yading@10: plot(axis_peak,pphase(1:num_peak),'rx');%Phase peaks 
yading@10: 
yading@10: pin = pin+H; % advance sound pointer
yading@10: end